Power injectors for injecting fluid into animals are well known in the art. A typical power injector comprises an injector head, having a syringe mount, and a drive ram reciprocally mounted thereon. This syringe is mounted to the injector in either a breach-load manner or a front load manner. The syringe can either be pre-filled or empty, i.e., the user must first draw contrast into the syringe before injecting fluid.
Syringes for power injectors are also well known in the art. As stated in the preceding paragraph, the syringe can be a front load type, in which the rear end of the syringe is inserted into the injector to attach the syringe to the injector. Additionally, the syringe could be breach loaded, such that, for example, a face plate of the injector is rotatable and the syringe is loaded through the rear the face plate, front end first.
A drive ram of the injector may attach to the plunger of the syringe to move the plunger forward relative to the syringe, to expel fluid from the discharge end of the syringe. In typical injection procedures, the pressure generated by the forward translation of the plunger can range from about 100 psi to 1200 psi. To ensure that contrast fluid from the syringe does not leak past the plunger, plunger assemblies typically comprise at least two (2) integral sealing rings that contact the inside surface of a syringe barrel. Typically, the forwardmost sealing ring performs the majority of the sealing process, and the rearward most sealing ring is a backup safety seal in case the forwardmost ring fails.
One problem with the plungers having two (2) seal sealing rings is that, once installed in the syringe, sterilization of the area between the two (2) sealing rings is difficult. With most materials, it is difficult for the sterilization gas to reach the area between the two (2) sealing rings. Accordingly, there is a need for a syringe jacket (seal) that overcomes the deficiencies in the prior art. This design eliminates the difficult-to-sterilize space between the two seals when the plunger is installed in the syringe. Accordingly, the present invention is hereby presented.